Change pop mutator to call remove mutator.

Change `remove` and `removeBatch` behavior to set array value to undefined when all items have been removed.

Author: huan086

src/pop.js

@@ -1,37 +1,17 @@
 // @flow
 import type { MutableState, Mutator, Tools } from 'final-form'
-import { escapeRegexTokens } from './utils'
+import remove from './remove'
 
 const pop: Mutator<any> = (
   [name]: any[],
   state: MutableState<any>,
-  { changeValue }: Tools<any>
+  tools: Tools<any>
 ) => {
-  let result
-  let removedIndex: ?number
-  changeValue(state, name, (array: ?(any[])): ?(any[]) => {
-    if (array) {
-      if (!array.length) {
-        return []
-      }
-      removedIndex = array.length - 1
-      result = array[removedIndex]
-      return array.slice(0, removedIndex)
-    }
-  })
-
-  // now we have to remove any subfields for our index,
-  if (removedIndex !== undefined) {
-    const pattern = new RegExp(
-      `^${escapeRegexTokens(name)}\\[${removedIndex}].*`
-    )
-    Object.keys(state.fields).forEach(key => {
-      if (pattern.test(key)) {
-        delete state.fields[key]
-      }
-    })
-  }
-  return result
+  const { getIn } = tools;
+  const array = getIn(state.formState.values, name)
+  return array && array.length > 0
+    ? remove([name, array.length - 1], state, tools)
+    : undefined
 }
 
 export default pop

src/pop.test.js

@@ -23,7 +23,7 @@ describe('pop', () => {
         }
       }
     }
-    const result = pop(['foo'], state, { changeValue })
+    const result = pop(['foo'], state, { changeValue, getIn, setIn })
     expect(result).toBeUndefined()
     expect(changeValue).toHaveBeenCalled()
     expect(changeValue).toHaveBeenCalledTimes(1)
@@ -33,71 +33,59 @@ describe('pop', () => {
   })
 
   it('should return undefined if array is undefined', () => {
-    const changeValue = jest.fn()
+    // implementation of changeValue taken directly from Final Form
+    const changeValue = (state, name, mutate) => {
+      const before = getIn(state.formState.values, name)
+      const after = mutate(before)
+      state.formState.values = setIn(state.formState.values, name, after) || {}
+    }
     const state = {
       formState: {
         values: {
-          foo: ['one', 'two']
+          foo: undefined
         }
       },
-      fields: {
-        'foo[0]': {
-          name: 'foo[0]',
-          touched: true,
-          error: 'First Error'
-        },
-        'foo[1]': {
-          name: 'foo[1]',
-          touched: false,
-          error: 'Second Error'
-        }
-      }
+      fields: {}
     }
-    const returnValue = pop(['foo'], state, { changeValue })
-    const op = changeValue.mock.calls[0][2]
+    const returnValue = pop(['foo'], state, { changeValue, getIn, setIn })
     expect(returnValue).toBeUndefined()
-    const result = op(undefined)
+    const result = state.formState.foo
     expect(result).toBeUndefined()
   })
 
   it('should return empty array if array is empty', () => {
-    const changeValue = jest.fn()
+    // implementation of changeValue taken directly from Final Form
+    const changeValue = (state, name, mutate) => {
+      const before = getIn(state.formState.values, name)
+      const after = mutate(before)
+      state.formState.values = setIn(state.formState.values, name, after) || {}
+    }
     const state = {
       formState: {
         values: {
-          foo: ['one', 'two']
+          foo: []
         }
       },
-      fields: {
-        'foo[0]': {
-          name: 'foo[0]',
-          touched: true,
-          error: 'First Error'
-        },
-        'foo[1]': {
-          name: 'foo[1]',
-          touched: false,
-          error: 'Second Error'
-        }
-      }
+      fields: {}
     }
-    const returnValue = pop(['foo'], state, { changeValue })
-    const op = changeValue.mock.calls[0][2]
+    const returnValue = pop(['foo'], state, { changeValue, getIn, setIn })
     expect(returnValue).toBeUndefined()
-    const result = op([])
+    const result = state.formState.values.foo
     expect(Array.isArray(result)).toBe(true)
     expect(result.length).toBe(0)
   })
 
   it('should pop value off the end of array and return it', () => {
-    let result
-    const changeValue = jest.fn((args, state, op) => {
-      result = op(['a', 'b', 'c'])
-    })
+    // implementation of changeValue taken directly from Final Form
+    const changeValue = jest.fn((state, name, mutate) => {
+      const before = getIn(state.formState.values, name)
+      const after = mutate(before)
+      state.formState.values = setIn(state.formState.values, name, after) || {}
+    })  
     const state = {
       formState: {
         values: {
-          foo: ['one', 'two']
+          foo: ['a', 'b', 'c']
         }
       },
       fields: {
@@ -113,7 +101,8 @@ describe('pop', () => {
         }
       }
     }
-    const returnValue = pop(['foo'], state, { changeValue })
+    const returnValue = pop(['foo'], state, { changeValue, getIn, setIn })
+    const result = state.formState.values.foo
     expect(returnValue).toBe('c')
     expect(Array.isArray(result)).toBe(true)
     expect(result).toEqual(['a', 'b'])
@@ -161,7 +150,7 @@ describe('pop', () => {
         }
       }
     }
-    const returnValue = pop(['foo'], state, { changeValue })
+    const returnValue = pop(['foo'], state, { changeValue, getIn, setIn })
     expect(returnValue).toBe('d')
     expect(Array.isArray(state.formState.values.foo)).toBe(true)
     expect(state.formState.values.foo).not.toBe(array) // copied
@@ -238,7 +227,7 @@ describe('pop', () => {
         }
       }
     }
-    const returnValue = pop(['foo[0]'], state, { changeValue })
+    const returnValue = pop(['foo[0]'], state, { changeValue, getIn, setIn })
     expect(returnValue).toBe('d')
     expect(Array.isArray(state.formState.values.foo)).toBe(true)
     expect(state.formState.values.foo).not.toBe(array) // copied

src/remove.js

@@ -9,11 +9,17 @@ const remove: Mutator<any> = (
   { changeValue, getIn, setIn }: Tools<any>
 ) => {
   let returnValue
-  changeValue(state, name, (array: ?(any[])): any[] => {
-    const copy = [...(array || [])]
+  changeValue(state, name, (array: ?(any[])): ?(any[]) => {
+    if (!array) {
+      return array
+    }
+
+    const copy = [...array]
     returnValue = copy[index]
     copy.splice(index, 1)
-    return copy
+    return copy.length > 0
+      ? copy
+      : undefined
   })
 
   // now we have to remove any subfields for our index,

src/remove.test.js

@@ -46,8 +46,7 @@ describe('remove', () => {
     expect(returnValue).toBeUndefined()
     const op = changeValue.mock.calls[0][2]
     const result = op(undefined)
-    expect(Array.isArray(result)).toBe(true)
-    expect(result.length).toBe(0)
+    expect(result).toBeUndefined()
   })
 
   it('should remove value from the specified index, and return it', () => {

src/removeBatch.js

@@ -59,7 +59,9 @@ const removeBatch: Mutator<any> = (
       copy.splice(index, 1)
     }
 
-    return copy
+    return copy.length > 0
+      ? copy
+      : undefined
   })
 
   // now we have to remove any subfields for our indexes,

src/shift.test.js

@@ -46,8 +46,7 @@ describe('shift', () => {
     expect(returnValue).toBeUndefined()
     const op = changeValue.mock.calls[0][2]
     const result = op(undefined)
-    expect(Array.isArray(result)).toBe(true)
-    expect(result.length).toBe(0)
+    expect(result).toBeUndefined()
   })
 
   it('should remove first value from array and return it', () => {